The human skeleton is composed of 206 individual bones that perform a variety of important functions, including support, movement, protection, storage of minerals, and formation of blood cells. To ensure that the skeleton retains its ability to perform these functions, and to reduce pain and disfigurement, bone's that become damaged should be repaired promptly and properly. Typically, a fractured or cut bone is treated using a fixation device, which reinforces the bone and keeps it aligned during healing. Fixation devices may include external fixation devices (such as casts and fixators) and/or internal fixation devices (such as bone plates, nails, and bone screws), among others.
Bone plates are sturdy internal devices, usually made of metal, that mount directly to the bone adjacent the fracture (or osteotomy). To use a bone plate to repair a discontinuity of a bone, a surgeon typically (1) selects an appropriate plate, (2) reduces the discontinuity (e.g., sets the fracture), and (3) fastens the plate to bone portions disposed on opposite sides of the discontinuity using suitable fasteners, such as screws and/or wires, so that the bone portions are fixed in position.
Despite direct access to the bone portions when applying a bone plate, the surgeon may have difficulty fixing the bone portions with the correct alignment. For example, one or more of the bone portions may be relatively small and/or displaced from the bone plate. As a specific example, in fixation of fractures of the distal radius, a distal bone fragment may be difficult to position properly. More generally, during attachment of any bone plate, fasteners may be misplaced or misdirected so that bone portions move away from a desired positioning as the fasteners are tightened. Accordingly, the relative position of bone portions may need to be adjusted as the bone plate is being secured to a bone to achieve proper reduction of a bone discontinuity.